Oil bag. 'Mariner's Mirror' Feb, 2010, p.94. Captain J.W. Martin 'they were carried as part of the ship's lifeboat equipment and were primarily intended to be deployed in conjunction with a sea anchor to mitigate the effect of seas breaking inboard when hove-to or running before a swell. The lifeboat's sea anchor ( a canvas drogue, attached to a rope hauser and fitted with a light tripping line) would be deployed to windward. During deployment the oil bag would be atttached to a suitable point on the hawser by an endless whip, thus allowing recovery for replenishment. Prior to attachment the canvas bag would be pricked by a sailmaker's needle to allow adequate release of oil. In my experience the oil bags were usually filled with oakum (teased rope fibres), and /or cotton waste, and fish oil was indeed the preferred (and cheapest) medium used. Wave-quelling oil could also be used to advantage when launching or recovering ship's boats, embarking or disembarking a pilot or, in similar vessels, where lying to anchor in exposed anchorages.' Lifeboats were required to carry them until 1998.